How can I mirror an object relative to a chosen point, in 3D space?
Blender allows you to manipulate center points instead of the whole objects.

Set Manipulate Center Points, then mirror the objects: the geometry will not change.

CAVEAT: Since it will manipulate individual origins, you have to separate all the components of your model before mirroring.



If you want to "reverse" the order of the object, set Pivot Center to Bounding Box Center, then mirror the objects along the desired axis.





Shortcuts for these examples

Toggle Manipulate Center Points: Alt + ,

Set Pivot Center to Bounding Box Center : ,

Set Pivot Center to 3D Cursor : .

Mirror along X-Axis: Ctrl + M, X